William clabk



3 Sheets-Sheet 1.

(No Model.)

vW. CLARK.

STEAM BOILER.

No. 315,243.Y U

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3 Sheets-Sheet 2. W. CLARK.

' STEAM BOILBR. No. 315,243. Patented Apr. 7, 1885.

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. 3 Sheets-Sheet 3. W. CLARK.

STEAM BILER.

(No ModeL) Patented Apr. 7, 1885. Y

S. Pmwumo UNITED STATESV PATENT OFFICE.

WILLIAM CLARK, OF-PLUMSTEAD, ENGLAND.

v STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No.315,243, dated April 7, 1885.

Application led J une 24. 1884.

(No model.) Patented in England March 31, 1884, No. 5,714, andin Belgium March 31, 1884.

.To all whom, it may concern:

Be it known that I, WILLIAM CLARK, engineer, a subject of the Queen of GreatBritain, residing at Plumstead, England, have invented new and useful Improvements in and Relating to the Construction and Heatingof Steam-Boilers, (for which I have applied for provisional protection in Great Britain on the 31st day of March, 1884, No. 5,714, and for which I have obtained a patent in Belgium dated March 31,1884, No. 64,686B,) of which the following is a specification, reference being had to the accompanying drawings.

My invention has for its object to increase `the heating-surfaceof flue-tubes foI` steamboilers and to strengthen the same, to offer great resistance to compression, and also to retard the movement of currents of heated air and gas and compel them to remain longer in the ilues and around the boiler, thereby the more fully to utilize the heat generated in the furnace.

My invention may be conveniently and advantageously carried into practice in the 1nan ner illustrated in the accompanying drawings,

. in Whichor plates are usually joined together.

Figure l is a longitudinal central section of a boiler embodying my improvements. Fig. 2 is a transverse section of the same. Fig. 3 is a horizontal section of part of the said boiler. Fig. 3 is a section showing the manner in which the water-tubes and angle rings Fig. 4 is a side elevation, partly in section, drawn to an enlarged scale, showing a modified form of my improved flue-tube. Fig. 5 is a side elevation of a flue-tube provided with wateri tubes, as hereinafter described. Fig. 6 is a tubes, through which the water in the boiler will circulate, and upon the exteriorof whichl the heated air and gases in the said furnace or fine-tube will act, so that the heating-surfaceV of the boiler is greatly increased. The fiuetubes shown in Figs. l, 2, and3 are made in sections; lbut instead of being of the same diameter throughout the alternate sections are made of different diameters-that is to say, there is a large section, a, between two small sections, b, and each large section has extending longitudinally through it a series of watertubes, c, opening at their ends just outside of the adjacent small sections and fixed in double angle-iron rings or plates d. The saidwatertubes c, therefore, are in connection With and lled by the water in the boiler, and the heatcurrents in the liuc act not only upon the surface of the fine-plates c and b, but also all around the water-tubes c. By constructing the flue tube or tubes of a boiler in this manner I greatly augment the heating-surface thereof and obtain an increased evaporation of the water in the boiler with less vconsumption of fuel.` The plates dare usually swaged or bent outward around'the holes, as

shown yin Fig. 3, so that the tubes can be easily fitted therein and made water-tight. In some instances I make the ues in both the large and small sections plain; but for iues of large diameter I form the various sections of the flue-tubes with undulations or corrugations; or I form the flue-sections into bulbous or barrel-shaped iigures,as shown in Fig. 4 that is to say, I rst form the sections of plain plates with welded joints. I then place them in a furnace until the required heat Y is ob` tained and pass them through a set of rolls, which are so constructed as to impart to the plain circular plates the required bulbous, corrugated, or other shape, leaving a plain or parallel part at each endto form a lap riveted or other joint; or, if desired, the fine-sections c b are the bulbous or barrel-shaped portions, and a2 b2 the plain or parallel parts for the joints. By this form of construction I increase the resistance of the said sections to external pressure, and I am thus enabled to make them of thinner plates than would otherwise be the case.

According to another modification of my invention, instead of arranging the water-tubes longitudinally, as above described, I make the said tubes bent or curved to correspond with the circumference of the Hue-tube and insert them therein. I sometilnes form flue-tubes by rolling or otherwise into a series of regular or irregular corrugations with plain portions, into which curved water-tubes are inserted, as shown in Fig. 5, in which ff are the corrugations, g gthe plain portions, and h h the curved water-tubes.

'Ihe flue-tube shown in Fig. 5 is formed by means of rolls, such as those shown at h3 71.4 in Fig. 9. The whole length of the ue or any part of it may be provided with these curved water-tubes. The said tubes may be connected to the iuetubes at two or more points; but I prefer to connect them at three points, as shown in Fig. 7-that is to say, the two ends of the said water-tubes are connected to the flue-tubes at a convenient distance from the bottom or lower part of thesame, as shown at h', and the intermediate portion of the watertube is connected with the top or crown of the said due-tube, as shown at h2. Suitable holes are formed in the iue-plates for the reception ofthe said ends and intermediate portion of the water-tubes, the metal around them being swaged or bulged up to thicken and strengthen the plates at the parts that receive the said water-tubes, which may be expanded and ixed in the said holes, according to the well-known method of fixing tubes in boilers. Ihe water enters the bent tubes at the two ends and escapes at the top aperture. I thus insure a continuous circulation from the lower to the higher parts of the boiler and a very rapid evaporation of the water. The aforesaid bent or curved water-tubes can be conveniently iixed to existing ordinary plain cylindrical flue-tubes without removing them from the boiler by simply pressing the ends of the tube toward each other, so that it can be inserted in the flue-tube and will then expand; and when properly arranged these water-tubes will insure a very efficient action of the heated currents in passing along the flue and a more rapid evaporation of the water in the boiler. This form of construction is shown in Figs. 6 and 7, in which i' is the flue-tube, and h h are the water-tubes. Y

I sometimes provide the flue-tubes with a series of plates or shields to retard the passage of the heat and cause the heated currents to impinge more effectually upon the flue-plates and water-tubes. If desired, I may employ, in combination with the longitudinal water-tubes shown in Figs. 1 to 3, bent or curved water-tubes arranged around or partially around the interior of the small sections of the flue-tube, so as to still further increase the heating-surface.

In Figs. 1 and 2, k 7c are the said shields or plates, which arc mounted on arms or levers Z, hinged or jointed to eyes or eyebolts m, fixed in the fiue. These arms or levers are connected by links n, and a rod or bar, o, is attached to the first of the said arms or levers and extends to the front of the boiler, where it is conveniently arranged to be moved to and fro for the purpose of raising and lowering the said plates or shields, and thus regulating or controlling the passage of the heated gases or products of combustion through the flue. The rod o may be notched, as shown, so that it can engage with a stud or projection, p,- or other suitable means may be provided for securing the said rod in the desired position.

Instead of allowing the heated currents of thegases and smoke from the furnace to escape from the f lues, I provide for keeping them in circulation through the iues by means of an air propeller or circulator, by which they are caused to return below the furnace and up through the nre-grate. rIhe unconsumed gases thus having to pass up repeatedly through the fire-grate are quickly ignited and greatly increase the heat. This air propeller or circulator is shown at q, in Figs. 1 and 2, mounted on a shaft, r, which is carried in bearings s, and driven by means of the pulley t. A'damper or air-valve, u, is placed at the uptake or any convenient part, and another damper or air-valve, o, is placed in front of the propeller or circulator, so as to regulate the admission or passage of air to assist combustion. Vith this arrangement I can maintain a slow combustion in the furnace with great advantage, and in some cases I can work ICO with both dampers closed, the heated currents being kept in circulation by the propeller without being allowed to escape from the flues.

1. A liuc-tube having raised sections a and small sections b, arranged alternately, in combinationwith the angle-plates d, formed with flanges, as shown, and connecting the raised sections to the small sections, and tubes fitted within the raised sections, with their ends resting in said plates and opening outside of the small sections, substantially as described.

2. The combination, with a iuetube, of an arched water-tube located within the same and provided with extensions connecting said tube at its ends and a point intermediate thereof to the Hue-tube, and at such points communicating with the water-space outside of the flue-tube, substantially as described.

3. 'Ihe combination, with a due-tube consisting of large sections c and small sections b, as above described, of the plates or shields k, pivoted to the said large sections and arranged to be raised and lowered, substantially In testimony whereof I have hereunto signed as and for the purpose set forth. my name in the presence of two subscribing 4. The combination of the Hue-tube having Witnesses.

raised or enlarged portions, the retarding- 5 shields located therein, the Water-circulating WILLIAM CLARK.

tubes located inside the tube within such enlarged portions, and the air-propeller for re- Witnesses: turning the unconsumed gases back to the JOHN E. BOUSFIELD, lire-grate beneath the same, substantially as i ALFRED WAUGH.

1o and for the purpose set forth. 

